IN the mid-1980s, when I was in college, what concerned and frustrated my peers and me was how few states had basic statutes forbidding discrimination against gay men and lesbians: laws that merely prevented someone from being denied a job or apartment on the basis of whom he or she loved. At that point only Wisconsin and the District of Columbia provided such protection. The decade would end with just one addition, Massachusetts, to that meager list.

Same-sex marriage? I don’t recall our talking — or dreaming — much about that. We considered ourselves realists. Sometimes idealists. But never fantasists.

As it happens, we were pessimists, and underestimated our country’s capacity for change. That was my thought all week, even as it remained unclear what the endlessly dithering New York State Legislature would decide and even as President Obama, speaking at a gay gala in Manhattan, stayed the closeted pro-gay course, giving coy signals of solidarity without tying the knot. The fact that same-sex marriage was drawing such serious attention at such high levels was public proof of what I could see in my private life — in my own family. Where we are is a long way from where we were.

Outside New York, five states, along with Washington, D.C., already permit same-sex marriages. Twenty-one states, along with D.C., outlaw anti-gay discrimination. And both numbers will grow. That’s what recent polls telegraph, and that’s what the shape and flavor of the campaign for same-sex marriage in New York irrevocably demonstrated. This issue will increasingly transcend partisan politics and hinge less on party affiliation or archaic religious doctrine than on the intimate, everyday dynamics of family and friendship.

As The Times’s Michael Barbaro and Nicholas Confessore have reported, the biggest and most influential donors to the New York campaign were Republicans. A New York City mayor without any huge strategic stake in the matter devoted considerable money and muscle to it. And public-service announcements in favor of it were recorded not just by actors and artists but also by athletes like the hockey player Sean Avery, and by the city’s former police commissioner William J. Bratton.

Why such widespread backing, from such surprising quarters? One major reason is that the wish and push to be married cast gay men and lesbians in the most benign, conservative light imaginable, not as enemies of tradition but as aspirants to it. In the quest for integration and validation, saying “I do” to “I do” is much more effective — not to mention more reflective of the way most gay people live — than strutting in leather on a parade float. We’re not trying to undermine the institution of marriage, a task ably handled by the likes of Tiger Woods, Arnold Schwarzenegger, John Edwards and too many other onetime role models to mention. We’re paying it an enormous compliment.

But an even bigger reason is how common it now is for Americans to realize that they know and love people who are gay. AIDS had a lot to do with that. This month is the 30th anniversary of the disease’s emergence, a ghastly dawn chronicled in the current Broadway revival of “The Normal Heart.” And it’s worth pausing to note how drastically the epidemic raised the stakes of secrecy and silence, pulling homosexuals from the shadows. If we wanted people to take up arms against a scourge associated primarily with gay men, we had to make them appreciate how many gay men they were close to.

Over the last quarter-century the love that dared not speak its name turned into a veritable motor mouth, to a point where the average American, according to an astonishing Gallup Poll last month, thinks that about 25 percent of the population is homosexual. Hardly. But that perception underscores how visible gay people have become. And familiarity changes everything.

Same-sex marriage is personal for Governor Andrew M. Cuomo, whose longtime companion, Sandra Lee, has a gay brother. It’s personal for Paul E. Singer, the most impassioned of the Republican donors. At a fund-raiser for same-sex marriage last year, he recalled leafing through the wedding album of “my son and son-in-law,” married in Massachusetts. “At the moment they are pioneers,” he said, according to a transcript, “although I felt like a loving father and father-in-law, not a pioneer, as we were looking at the pictures.”

It’s personal for the New York Post columnist Andrea Peyser, who on Monday wrote, “I give in.” She recounted the recent Massachusetts wedding of her niece and another woman and said: “Despite abstract discomfort over normalizing gay unions, I don’t know of a soul who would discriminate against the nice guys next door. Nor would I deny my niece happiness that is evident in the size of her smile.”

In voicing his support for same-sex marriage, Mayor Bloomberg has mentioned — and appeared with — his niece Rachel, who is lesbian. “It brings it home,” he told me on the phone this week, though he added that beyond his desire for her to have everything she wants in life, “Government should not tell you what to do unless there’s a compelling public purpose.” He sees no such purpose in blocking same-sex marriage.

I asked Avery how he arrived at his support. He mentioned gay friends whose weddings he thinks it would be a blast to attend.

I asked Bratton. “My sister, Pat, is married to her partner in Massachusetts,” he said, adding that the two women have been together for decades and have a grown son.

To reckon with the gay people right in front of you is to re-examine your qualms. I’ve seen that in my father, a 76-year-old Republican.

Years ago he would quietly leave the room whenever my sexual orientation came up in a family conversation. But when he urged me to attend a Halloween party he gave for his friends last fall, he insisted I bring Tom, whom he has come to know well over the two and a half years we’ve been together. And as he introduced us to his golf partners from the country club, he said, “This is my son, Frank. And this is my other son, Tom. Or at least I think of him that way.”

Only once did he look unsettled: when he realized he hadn’t run that language by Tom. “I’m not making you uncomfortable, am I?” he asked him.

I called Dad the other day to get his permission to share that story. I also brought up something else — for the first time.

“Do you support gay marriage?” I asked him.

“I don’t know,” he said, explaining that it still seemed strange. He added: “But not if you know the person.”

“Meaning me?” I said.

“No,” he said. “I mean Tom. He’s a good person. If you and he got married? I guess that would be O.K. Yeah, that would be fine.”